A Pox On You
by Luki Dimension
Summary: Just because humanity was frozen in stone, doesn't mean everything else was. All sorts of new diseases have hit Ishigami Village over the years. And unfortunately for the depetrified, their immune system's are 3700 years out of date.


_Once upon a time in the FMA fandom, I read a fic about Ed crossing into 'our' world and becoming bedridden by all the foreign diseases he had no defence against. I always loved the idea, and given how new diseases are evolving all the time, I think it's safe to say there's a few that have appeared that Senku and the others wouldn't know to prepare for._

_That said, I have absolutely no scientific knowledge, so a lot of it is me trying to sound smart and succeeding maybe half the time. Enjoy._

* * *

In hindsight, Senku realises he should have seen it coming.

Things had been going far too well in the Kingdom of Science. They were finally making decent headway with the ship, small inventions were revolutionising Ishigami village every week, and both the natives and the depetrified were getting along just fine. Even Magma and Yo were cutting the bickering down to just once a week.

However, Senku's luck never stays that positive for long.

A week into the bitter winter chill that preludes snow, Senku, Chrome and Ukyo are inside the lab, going over a way to try and insulate the village huts better at Ukyo's request, when Yo and two other depetrified – Kodai and Higuro, former wrestlers and opponents of Tsukasa if Senku's memory serves – storm into the lab bitterly scratching at their wrists.

"Hey, Senku, you got anything for poison ivy?" Yo whines. "It's driving us crazy."

The scientist frowns, looking up from the papers.

"How did you manage to find poison ivy this close to the village?"

"I don't know!" Yo snaps. "There must have been some mixed up with the harvest, because all three of us have it."

Ukyo walks over, and lifts Yo's wrist.

"I don't see anything," he says, twisting the limb slightly. All Senku can see from his position is the red marks where Yo's tried to alleviate the itching. "Are you sure it was a plant?"

"Don't know what else it could be," Kodai says. "Maybe it's new around here?"

Senku hums, and turns to Chrome.

"Hey, you still have some of that clay we stored in the glass jar?" he asked.

"Oh, that really bad one you called bentonite?" Chrome says. "Sure thing."

"Great, go grab it, along with some salt and lavender oil, if we have any left," Senku orders. "I'll grab the baking soda, and we'll whip up some calamine lotion."

"You're the best, boss!" Yo, Kodai and Higuro cry.

* * *

"Calamine lotion?" Gen asks a few hours later, when he slips into the observatory and picks up one of the newly filled jars. Senku intends on handing out a few batches to the villagers later, but for now they're just stacked for storage. "What had you interested in making that of all things?"

Senku shrugs. "We needed some. Yo and some of the others got into poison ivy and ended up scratching. Wasn't too hard to make, and I figure it'll be useful if anyone gets a rash."

Gen however, looks up and frowns. "Poison ivy?"

"Yeah. Couldn't see any marks, but Yo was practically scratching his arm off."

The mentalist stays silent, glancing out the door towards the forest, and Senku can't help but follow his gaze.

"Gen?"

"I make a point of knowing the flowers in this area, Senku," Gen tells him, dropping the jar and tucking his arms into his sleeves. "I have never once seen any plant from the toxicodendron family outside of the lacquer trees. In addition – everyone has been wearing gloves since the frost hit."

Senku blinks. He's always been aware that Gen has at least a passing interest in botany. But he'd never realised it went deep enough to know the scientific terms.

"Say 'toxicodendron' again," he says slightly too eagerly, and Gen smirks.

"Get your science fix later, Senku-chan," he replies. "We have a mystery to solve. I find it very unlikely that anyone would somehow stumble upon a plant like that if I haven't. Granted, if anyone in this village was going to, it would be Yo, but still. Are we sure it was a plant?"

"...No," Senku admits, starting to get curious. He stands, hand at his chin as he thinks it over. "To be honest, I didn't actually see any rash. Yo and the others were just complaining that their wrists itched."

Gen makes a low hum in the back of his throat. "Perhaps the Ishigami residents know of something similar? It might be a common allergy."

It's a rational theory, but Senku doubts it – he's been in the village for nearly a year before the war with Tsukasa's empire and he's never seen it. Granted, he was more focused on helping Ruri at the time, but – surely Chrome would have recognised it when they walked in?

"I'll check in with them tomorrow," Senku decides. "The calamine lotion seemed to work, but if they're still itchy or have a rash in the morning, I'll try and do a full study."

* * *

At the time, waiting had seemed logical. Yo and the others had been uncomfortable, but not particularly bothered by their itch. It's a decision Senku starts to bitterly regret come the next morning, when none of the three show up to their shifts. When they track them back to their tents, Senku's heart sinks when he starts to pick up the smell of vomit.

Yo is pale white, but sweating like he's in a sauna, while Kodai is hugging a clay pot and dry heaving, and Higuro looks about ready to join both of them. More importantly, the invisible itch has become more blatant – deep red pockmarks on their wrists, and on their necks and faces.

"Crap, this is bad..." Chrome offers, face going as pale as Yo's.

"Okay," Senku admits, trying to find solid ground. "I don't think this is an allergic reaction."

Gen is hiding his mouth and nose with his jacket sleeve, scanning over them with sharp eyes.

"This is not poison ivy," he announces, as if Senku couldn't have figured that one out. "I don't suppose you've ever studied poisons, Senku?"

Senku grits his teeth. But before he can answer, they hear a voice call out.

"I don't think it's poison," Ukyo offers, walking up to them, and Senku and Chrome grimace when they see the man scratching at his wrist.

"Also, it looks like it might be contagious," Ukyo admits.

* * *

While none of the three are in any shape to move, Senku is not taking any chances, and begins planning. Somehow, Senku, Chrome and an enlisted Kohaku manage to coax them into one of the larger buildings that was quickly repurposed. Senku had made a point in getting them to dress head to toe in new fabric to keep themselves from catching it, and soon, Ishigami Village had their very first quarantine ward. If this is the start of an epidemic, Senku wants to know they have the space to keep anyone infected away from the village.

It's also why he requests Yuzuriha take some time to craft up several face masks and gloves, and makes an order to keep people out of the building without wearing them. Soap use is also mandatory.

Once that's done, he starts the investigation with the victim that's still functioning. Ukyo obediently sits on a hastily sourced table in a closed off room, and Senku begins the examination, armed with Chrome and Kohaku. He would have preferred Ruri, given her knowledge of the village, but no one in Ishigami is going to let the Priestess near an unknown disease at this point. However, his partner in science and Ruri's sister are a good second choice.

"It kind of looks like frostgrip," Kohaku mentions, picking up Ukyo's wrist. "But, I've never seen it on someone your age before."

"Yeah, it normally only happens to little kids," Chrome adds. "And it's never looks this bad."

"Frostgrip?" Senku asks, and Chrome nods.

"Oh, it's this really bad sickness that appears in the winter. It usually starts with your wrists and neck feeling itchy, and then the rash shows up."

"It's followed by a fever, an upset stomach, and a sore throat," Kohaku continues. "Our parents used to say the god of winter was trying to steal us away, and the rash came from where they'd tried to grab us. But if you could fight it off, they'd never try again. Nobody ever gets it twice."

Senku nods. "Okay, so it's a stone age version of chickenpox. Viral, not bacterial, and people develop immunity after contracting it once?

"Um...I don't know about most of that, but yeah, it's a one time thing," Kohaku agrees. "Most kids get it between 4 and 7. It's often fatal if you get it younger though."

"But this is seriously bad," Chrome argues. "The rash is never that red or vicious. And most kids can at least keep food down, even if they don't have an appetite."

Senku nods. "Yeah, but that's not surprising. Some diseases hit adults tougher than children. The one I mentioned before? Chickenpox? We had a vaccine, but for a long time, people would deliberately infect their kids with it, because science had gotten to a point where it was pretty easy to recover from, and it was ten billion percent worse to get it as an adult."

"Really?" Chrome repeats. "That's crazy."

"Well, you said you had, what was it? A vaccine?" Kohaku says. "Can't you make one now?"

"Easier said than done, I'm afraid," Ukyo tells her. "And it wouldn't do any good at this point. A vaccine is only useful before you're infected."

"He's right," Senku agrees. "And when it comes to treating, we'll have to be careful."

"What about the Cure-All Sulfa drug?" Chrome asks. Senku shakes his head.

"That's for a bacterial disease," he explains. "While I don't have the equipment to prove it right now, from what you've told me, this is a virus. Antibiotics won't have any effect."

"In fact, they might actually make things worse," Ukyo continues, staring down at his wrist, where the pock marks are starting to appear. "Taking antibiotics when you're not suffering from a bacteria can reduce their effectiveness for when you are."

Senku nods. "There's a few drugs we can offer them to relieve some of the symptoms, but all we can really do is keep the infected isolated, and away from the other depetrified. The villagers who've already had it should be safe, but we shouldn't take any chances. We need to check up on anyone who interacted with you or the others yesterday, and I'm not leaving this building."

"Why not?" Kohaku asks in confusion, but Senku can see comprehension dawning in Chrome's eyes.

"Oh man, you were treating them yesterday, and you helped them into here," he says. "You're probably infected."

"I don't know how long this is contagious, or how it spreads," Senku explains. "I have some ideas, but it's going to be hard to prove at this point. The two of you should be careful as well – just because you can't catch it, doesn't mean you can't carry it. For now, we need to find anyone who hasn't had frostgrip yet and has been in contact with Yo, Kodai, Higuro and Ukyo recently. If we can find patient zero, or just get them isolated, we can stop this from becoming an epidemic.

* * *

Turns out, the youngest kid in the village has frostgrip, and she's been hanging round the harvest teams at lunch time because they offer up stories of the before life with a less scientific angle. She however, has been holed up in her home with her parents ever since she symptoms started and is nowhere near as bad as the older victims. But it also means that they get several more infected through the doors, including, to Senku's utter dismay, Taiju and Yuzuriha.

"I thought idiots didn't get sick," Senku mutters, as he coaxes them over to empty beds. They'd brought in a few wall screens to separate parts of the building for their exam room, and to split people in different stages, but now he's got to worry about a female wing. At least for the first stage – once they start throwing up, he doubts anyone is going to care.

By the time Nikki has walked in with red wrists, Ukyo and a few of the others have fallen into the next stage – pale skin and a vicious fever. None of them have any appetite, and Senku's already requested a few more pots for when the vomiting starts.

He's in the corner they'd been using for examination, trying to figure out the stages, and what medicine they can use. They're almost completely out of the calamine lotion, even with Chrome hastily running out for another supply run, and he's bitterly regretting not stocking up on more of the medications. Dammit, he's knows how dangerous getting sick is right now, and there's no way they have enough if every single revived currently in the village falls ill. Let alone everyone currently in Tsukasa's former kingdom.

"Senku-chan, are you in here?"

He lifts his head up and scowls as Gen saunters behind the wall screen, decked in gloves and a face mask.

"You shouldn't be in here," he warns, dropping the pencil and crossing his arms. "If you're not suffering from symptoms, get out."

"Now, now, I'm being perfectly careful," Gen offers, wiggling his glove-clad fingers in his direction. "Besides, Kaseki and Chrome are in full labour mode, and I like my chances of avoiding being volunteered in here more."

Senku rolls his eyes. "Only you would choose getting sick over work."

"Look whose talking," Gen chimes, dragging over a seat over and sitting next to him. "You could have hidden out in the lab in your own quarantine, but instead you just threw yourself into the lions den."

"Ukyo barely touched Yo and came down with it," Senku counters. "The odds are against us here, our immune systems don't have any kind of resistance to this. It's a matter of when, not if. To be honest, I'm kind of surprised I'm not showing symptoms yet.'

Gen just stares at him, and with a graceful fingers, points at Senku's chest. Senku drops his eyes-

And finds his right hand scratching at his left wrist, having dug under the glove to get to the skin.

Senku freezes, before groaning and cracking his neck.

"Great. That's just fantastic."

He stands and starts grabbing the glass utensils on the shelf, suddenly grateful Chrome had brought some in so Senku could work while he waited out the symptoms.

"Make yourself useful mentalist," he warns. "I've got maybe 12 hours before I'm a feverish mess, so we're on bulk pharmacy duty."

"Ruly-tay?" Gen whines. "Isn't the sick making the medicine fairly counter productive?"

Senku just glares at him and points over at a basket in the corner.

"Supplies, Gen. Trust me, you'll be wanting them yourself soon enough."

Gen pouts, but obeys, and Senku turns to grab the last jar of calamine for his own wrists. He hates that Gen has a point, but they don't have the numbers. They'll just have to take the chance.

* * *

Senku doesn't quite remember when he fell asleep, which is enough to put him in a panic these days. He quite vividly remembers Chrome returning and getting quite upset, and someone else talking...but it's rather muted. When he wakes up, he's lying on the floor under a blanket, his wrists unbearably itchy, and his body feels like he's somehow both trapped in a freezer and right next to a bonfire.

The groan he makes doesn't even sound human, but almost immediately, there's a wet cloth on his forehead.

"Easy, Senku-chan," Gen soothes, eyes smiling. "You passed out a few hours ago. Chrome had to carry you to bed. How are you feeling?"

Like he's gone another few rounds with Hyoga and hit with his own stun gun, but when he tries to articulate that, his throat goes on strike, and he moans again.

He's immediately coaxed into a sitting position, and Gen is offering him water. If what Senku remembers about what he'd worked out, he's only got a few hours before he starts suffering gastronomic distress, so it's best to hydrate now, even if the task takes a herculean effort.

He tries to distract himself from the task by glancing around the dark room. Nearly every inch of the floor is covered in futons, but only about half of them are full. Taiju is in the bed next to him, dead to the world.

"How...how is everyone doing?" he chokes out, once his throat's lubricated. Gen's eyes flit to the side, and Senku sags.

"Everyone that was already down is still in full fever," Gen admits. "Though Kodai did manage to keep some soup down earlier, so he might be over the worst of it."

"Nobody's gotten worse though, right?" Senku clarifies.

"Well...nobody that was already down," Gen explains, and Senku glances over at the area left for newer victims.

He catches sight of a very distinctive hat, and falls down on his back again.

"Ryuusui?" he moans.

"And Francois," Gen adds, wincing as Senku stares at him in horror. "They came in just as you were nodding off. Chrome didn't take it well, I'm rather surprised you slept through it to be honest."

"How?" Senku almost whines. "They weren't anywhere near the harvest team!"

"Apparently, you were right about people being able to carry it without getting infected," Gen explains. "Our patient zero wasn't the only child in the fields, just the only one who hadn't had it yet. By the time we realised, it was too late."

Senku growls and covers his face with his hands.

"This is going to take out everyone," he says, idly scratching at the pockmarks on his chin. "Tell me we've still got a block on travel between the Kingdom of Might."

"Oh don't worry," Gen assures him, quickly pulling the hands away. "Everyone is staying clear for now. The children feel just_ awful_ about setting the frost gods on us, so they're being very gung-ho about contacting everyone and letting them know what's happening. As well as chasing people to wash their hands and making new face masks."

"I'm surprised you're not feeling awful yourself," Senku says, letting his hands drop and frowning. The room is dark, and Gen isn't exactly tanned, but he does look a little paler than usual. "How are you not itching at this point?"

"What can I say, I have a fantastic immune system," Gen says with glee.

"Bull," Senku mutters, and pulls his blanket further up. "Where's Chrome and Kohaku?"

"Well, now that Francois is sick, Kohaku's been put in charge of storing anything they were preparing," Gen explains. As if summoned by their name, the chef appears at the edge of the wall screen, dressed in basic blue like the rest of them.

"I was deep in food preparation, but if Kohaku works quickly, most of the storage and cooking can be salvaged," Francois explains. "It's very embarrassing, for a butler to fall during such an important task."

There's a chuckle behind them, and Ryuusui's head pops out.

"I'm a little upset I wasn't the first, but I may be the last. We have the rest of the ship builders under Kaseki and under strict observation."

That...that's relieving. They really don't have enough room in this building to support the handful of members who haven't fallen sick now.

Ryuusui then turns his attention to Senku, looking down in sympathy.

"How are you doing, Senku?" he asks. Senku just shakes his head.

"Not looking forward to the next few days."

"Trust me, it's as bad as it looks," comes a whine from the corner of the room – it says a lot about how dry the throat is that Senku isn't sure who said it.

"I need to talk to Chrome," Senku says, trying to sit up again. "We need to set up a plan for-"

Gen doesn't even let him finish, a hand on his chest and forcing him back down with little effort – though his arm is definitely shaking more than it should be. Before he can even attempt to fight him off, Ryuusui is there too, practically tucking him in and fluffing his pillow.

"What you need to do is rest, Senku," Ryuusui explains. "The more you rest, the faster you'll recover. And that's definitely something we should rush."

"Enjoy this part of the infection Senku-chan," Gen jokes. "Take the opportunity to sleep. It's going to be a lot harder come stage 3."

The idea sounds overwhelmingly appealing, but he can't just lie here when his brain is still functioning. He tries to pull his arms out-

Only to find one arm pinned down, leaving him trapped to the ground. When he turns his head, he finds it wrapped up in one of Taiju's own.

"You ass. You're not sleeping," Senku growls. Taiju bits his lip, but it's not enough to hide the smile, even if he refuses to open his eyes.

Gen chuckles. "Looks like you're in good hands Senku-chan. Come Ryuusui, let's get you settled back down."

Senku's face falls as Gen pulls Ryuusui back to Francois, and then turns back to look at Taiju. He gives his arm an experimental tug, but it doesn't shift.

Well, maybe they have a point about getting rest. His eyes do feel a little heavy...

* * *

A day later, Senku is hugging a pot so closely it's a miracle he hasn't cracked it yet. On the plus side, there's very little in it. The villagers have been quick to swap them out to reduce the smell, and all that's been thrown up in the last few hours is bile because he hasn't eaten anything.

He pulls back, his forehead resting on the outside of the pot with a groan. Damn does his head hurt.

"This sucks."

"I can't disagree," Ukyo mutters, leaning against a wall, a pot by his side. "Back in the before, I took my health so seriously. I'd spend months trapped in a steel box with a dozen other men, I had to. Every vaccination, every vitamin – I'd almost forgotten what is was like to get completely floored by a stupid bug.

Senku's lips twitch.

"Same here," he says. "I knew all the symptoms and the necessary cures, so I could always spot the signs in time to hold it off. And Byakuya was big on vaccines."

"Yeah, you never did get sick, huh Senku?" Taiju offers, lifting his head. He's lying flat on his back – the stupid idiot apparently got lucky and hasn't been hit with the vicious nausea, but he's still got the fever and the sore throat. "You were always so careful, and yelled at me whenever I came down with it."

"Eally-ray?" Gen asks, popping into the room with Chrome, whose carrying a small basket. "I thought idiots couldn't get sick?"

"Oh trust me, every cold, every flu, Taiju managed to catch," Senku says, eyeing the glass jars in the basket. "He's too damn nice to avoid people showing symptoms, so it would be up to me to force him to stay home before he took out the school. What have you brought, mentalist?"

"Well, our modern day medication is starting to get a little slim," Gen explains, and opens a jar. "So, I talked Chrome into using some of their own treatments."

Senku feels himself smiling. "Right, let me guess, sweet root?"

"Yup," Chrome says with an eager grin. "Works pretty well on upset stomachs. Gen also found this other plant he says might help."

Gen hands over the glass, then slips his gloved hands back into his sleeves, as Senku inspects the skinny slices of a root.

"Ginger, huh?" he says.

"We normally use it for cooking," Chrome says. "But Gen says it can help when you're sick too."

Ukyo is already grabbing a slice, but Senku ignores it, opting for the sweet root. He probably wont keep it down, but at least the supplies are pretty plentiful.

"We're also making some soup for the others tonight, just in case they feel up for eating something," Chrome offers, and turns to Gen.

"Hey, we'll bring some for you too, if you're still not risking coming out. I'll get Kohaku to bring lunch later."

"Oh, that's perfect," Gen says. "Just have her leave it in the exam room. For now, leave the medicine to me. You have plenty on your plate."

Chrome grins and stands up. "Great, thanks a bunch. I'll check in later, Senku. Hang in there!"

Senku haphazardly raises a hand, and lifts up a cup. His stomach immediately churns at even the thought, but it doesn't do him any good outside the body. It tastes just awful, but it doesn't immediately activate his gag reflex, so that's a plus.

"Well, try and keep this down, if you can," Gen says, handing Taiju a cup. "I'll go see if the others are happy to try alternative remedies."

His eyes take a wicked gleam.

"If I voice it right, I might even get Ryuusui to pay for it."

All of them offer a weak smile as the mentalist stands and heads away.

"I know I'm not exactly functional right now, but does Gen sound right to you?" Ukyo asks, after a moment. "His voice sounds off."

Senku frowns. He hadn't spotted anything, but neither of them are at their best – and Ukyo's ears aren't easily fooled.

"He's pale too," Taiju mumbles, sitting up with a moan. "Like, really pale. Are we sure he's not sick too?"

"If he is, he's hiding it like a champion," Senku concludes. "By all accounts, he should be sick by now, but he hasn't missed a step."

But isn't that suspicious in it's own way? Gen isn't exactly the hardiest of the depetrified – and the man lies like he breathes. But...why would he even bother to hide it?

Unfortunately, that mystery will have to wait, because his stomach has once more begun to protest, and he's miserably reaching for the pot again.

* * *

It's not until the evening that Senku has a chance to chase the mentalist on his health. While Gen remains in the building, he's busy flitting between the sick and the exam room, passing medication or taking breaks. There's not a chance to question him – but Senku does notice that Gen seems to wait an awful time to go grab the meals brought in for him, and he's never actually seen him eat one. Though he does catch him drinking something on occasion.

Gen also appears to realise Senku suspects something. He's avoiding him like – ironically – the plague. However, when Gen makes his next round of medications, Senku forces himself into a sitting position, and tries to grab Gen's wrist.

Only Gen quickly shifts and fills Senku's hand with a cup.

"Oh, someone's eager for their next dosage, Senku-chan," Gen jokes. "Here Taiju, for you."

Senku frowns as Gen leans over him to hand a cup to an eager Taiju. Then stops, and sniffs.

His sense of smell isn't exactly up to par right now, but Gen smells an awful lot like lavender. Granted, the mentalist generally has a floral scent thanks the number of flower petals he carries on his person, but lavender isn't one he prefers.

Actually, now that he's looking, he thinks he sees a pinkish stain just on the edge of Gen's high collar.

Senku's eyes narrow as the mentalist shifts back and shuffles through the basket.

"Gen."

The mentalist glances over, smiling behind his mask.

"Yes, Senku-chan?"

"Show me your wrists," he says. Gen blinks, and chuckles.

"I think you have enough patients to deal with before looking for extras, Senku."

Senku's just keeps glaring. "You've been in here ever since I started showing symptoms, you've got lotion on your collar, and you've been making a point to keep your hands out of sight. I'm sick, not blind."

"And I'm not deaf," Ukyo mutters from where he lies, eyes closed. "Your voice has been off all day. You're altering it to hide how dry your throat is."

"It appears this fever of yours is prone to strange hallucinations," Gen replies, though Senku notes he's quick to shuffle out of his reach. "I'm perfectly fine."

Now that he's actively looking, Ukyo definitely has a point. Gen's going for his more saccharine airhead tone, and it's its not as smooth as it should be.

"Gen-"

The door opens, and Senku scowls as Gen struggles to his feet, nowhere near as graceful as he'd probably hoped, to greet Chrome.

"Hey, I brought the soup," he calls, lifting up a steaming pot. "Anyone hungry?"

A cacophony of moans follows the request, and the scientists face falls along with the pot.

"Dammit. Nobody?"

"Afraid they're still all struggling to keep water down," Gen admits, walking up to him. "Perhaps we'll be lucky in the morning."

Chrome sighs, but pastes a smile on his face regardless.

"Yeah. At least you'll take a bowl right? Show em what they're missing."

Gen smiles. "Of course. Just leave it in the back and I'll grab it once I've made sure nobody wants to try."

"Why wait?"

Gen freezes, and glances over at Senku, whose watching the two with an evil smirk.

"What?"

"Humour me," Senku says. "Eat it in here."

The mentalist chuckles. "I don't think that would be very hygienic of me Senku-chan."

"Why not?" Senku counters. "We'd be eating in here if we could keep anything down. Pour him a bowl Chrome."

Chrome looks confused behind his mask, but obeys the order. Gen's eyes flit between him and Senku, before he realises half the room is watching him. Taiju's pulled himself up into a seated position next to Senku, and even the girls are peeking out behind their wall. His shoulders drop slightly, but he takes the bowl from Chrome without complaint.

"What exactly is going on?" Chrome asks, as Gen pulls down his mask – his skin looking even paler now that the black scar on his face is in view.

"Just an experiment, Chrome," Senku says.

'_To see how stupid a certain idiot magician might be.'_

He's never seen anyone look so hesitant at a bowl of soup, but Gen hides the reluctance well as he lifts it to his lips and takes a deep sip. Credit it to him, he's actually drinking it. When he drops it down, he cocks his head and smirks at Senku.

"Satisfied?"

Senku keeps looking at him. Taking in the pale complexion and the shaking arms.

"Sure," he replies. "So long as you stay in here long enough to prove it digests."

Gen freezes, smile falling. Senku's eyes narrow.

"That a problem?"

"Gen?" Chrome questions, and Gen hands him back the bowl. By this point, everyone still conscious in the room is watching the show.

"Dammit, fine," Gen mutters, voice raspy, and grabs the nearby pot. A second later, he's retching, throwing up the soup. Chrome winces and jerks away at the sound.

"Dammit mentalist," Senku mutters, dropping his head back down on his pillow. "Next time just admit you're as sick as the rest of us and don't waste food."

Gen drags his head up from the pot with a glare, opens his mouth to offer a retort – then immediately drops it back to continue emptying his stomach.

When the retching finally stops, Gen looks up to find Senku has pulled back the blanket on the futon arrange above his head, and is watching with an unimpressed glare.

Thankfully, Gen chooses to abandon all pretence of wellness, and staggers over, practically slipping out of the long overcoat and leaving it in an uncharacteristic pile on the ground, before dropping to his knees and falling face down on the mat. His hands fumble to pull off the calamine laden gloves, revealing the harsh red pockmarks on his wrists, that he's clearly scratched whenever his arms were hidden in his sleeves.

"Tell me you still have some of the aspirin you fumbled together," he mumbles into the pillow, head inches from Senku. "My head has been splitting open for the last 3 hours."

"It's your own damn fault," Senku croaks, but Chrome is already on the move, running back with the powder and some water, placing it into Gen's hand. "What were you thinking?"

The mentalist forces himself upwards to drink, his free hand pulling free the tight collar and revealing yet more pockmarks.

"I was thinking that dear Chrome and Kohaku are being run quite ragged trying to care for all of us. Having even one of the Kingdoms modern day 'Generals' walking around and looking just fine was excellent motivation for them."

"What! Seriously?"

Chrome flinches, and goes a little pale, but Senku isn't impressed.

"Even though it was killing you?" Senku snaps, and Gen scoffs.

"Don't be so melodramatic Senku-chan, that's my thing," he snipes. "It's hardly the first time I've had to work at less than my best. And if I can drag myself a hundred kilometres over wilderness after an assassination attempt, I can handle this."

"You idiot, that was a life and death situation," Senku says. "This is not the same thing."

Gen just rolls his eyes.

"Senku-chan, I am, first and foremost, a performer. It's a right of passage to pull off a several hour show with a fever in the triple digits without anyone being any wiser. I only needed to hold out until Ukyo started to recover, or at least the first wave of victims. Once they were on the mend, I could let myself fall ill."

Senku gives a rough laugh. "That's ten billion percent not how it works, mentalist. If you're sick, you rest, that's kindergarten logic."

Gen just groans and burrows deeper into his pillow.

"Someone has clearly never worked in the entertainment industry, Senku-chan. Now be a lamb and let me sleep."

In a matter of seconds, Gen's out cold, and Senku can only shake his head and look at Chrome.

"Sorry, looks like you'll have to find someone else to watch over us."

Chrome nods, though his eyes wont leave Gen's prone form.

"He kind of had a point," Chrome admits, and Senku frowns. "With everyone getting sick, we're kind of missing the manpower. The village had gotten so used to the extra hands, it's hard to keep up with the jobs. Having Gen in here really helped us out. We figured if he was still in shape, everyone else would be just fine."

Senku frowns, and at his side, Taiju leans over to pull Gen's hair from his face.

"Man, for a guy who insists he's super shallow, he really does care about people, huh?" he says. Senku smirks.

"Yeah..I'm pretty sure Gen is the only one in the village who still believes that line," he says. "Our mentalist lies to everyone, even himself."

They hear a raspy chuckle, and glance over to see Ryuusui watching them, hand on chin.

"I'm rather envious at his skill," he admits. "I didn't spot the signs even once. He's quite the master at hiding his weaknesses – he'd be terrifying in a boardroom."

"I wouldn't be too impressed," Senku warns. "He's probably going to take longer than everyone else to recover since he wasn't treating it."

"Wait, I know he wasn't resting, but what makes you so sure he-"

"Because our supplies are so low, someone would have noticed if we were missing a dose," Senku explains. "Unless he was supporting himself with-"

He stops, thinks about what he's saying – a lot harder with a fever and a headache – and scowls.

"Chrome, check the idiot's coat."

* * *

When Gen wakes up, it's to Kohaku bringing him a change of clothes, and he's treated to a whack on the head by Senku.

"You were treating yourself with your black nightshade?"

Gen doesn't even lift his head from the floor. "I couldn't take from the modern pharmacy supply without suspicion, so I improvised. Once I talked Chrome into bringing the medicinal herbs, I was able to get more creative."

"You really are an idiot," Kohaku mutters, all but throwing the fresh fabric at his head. Senku can't disagree.

"That's insane. Black nightshade might not be deadly, but it's ten billion percent toxic if it's not handled correctly."

He gets a harsh laugh in reply.

"Like the chemicals in your modern medicine aren't? I knew what I was doing Senku. It's been used as a medication for hundreds of years. I wouldn't have considered it if I didn't know exactly how to use it."

"Still a bonehead move, mentalist," he offers.

Kohaku shakes her head. "How fitting of the Mentalist, to use the flowers of liars to lie his way to health."

Gen cracks open one eye to look at her, and cracks a smile.

"Want to know a secret?" he rasps. "I lied."

"That's pretty par for course," Senku immediately jabs back. Gen snickers.

"Black nightshade," he explains. "It doesn't actually mean 'liar.' That's the meaning of deadly nightshade."

Kohaku frowns, and Senku blinks

"Oh?" Senku says. "Then what does black nightshade really mean?"

The mentalist smiles, and shakes his head.

"It doesn't have any hidden meaning, it's just a plant. But a lot of people mistake it for deadly nightshade, so nobody bats an eye when I use it and proclaim it the flower of liars."

Senku thinks about this for a moment, then huffs a laugh. Gen really must be feverish if he's spilling this.

"So, let me get this straight," he says. "Your precious nightshade, the flower that basically represents you, is a flower people often mistake for a deadly, poisonous plant that means falsehood, when in reality, it has no hidden meaning. It's just an extremely useful plant that's only dangerous if you don't know how to use it?"

He leans back, accidentally catching Kohaku's gaze, and the two of them start grinning.

"You know what, I think that suits you just fine, Gen," Kohaku offers.

"Still an utter idiot though," Senku says.

Gen hums, but doesn't argue it, and the lack of reply makes sniping at him rather pointless. So, when Kohaku steps away to treat the rest, Senku settles back and tries to figure out the next step in recovery.

Thankfully, while he still isn't ready to eat, his stomach has stopped trying to jump out his throat, so he's gotten better. Yo and the other's also don't sound quite as raspy, so they're probably on the mend too. As soon as one of them actually keeps a meal down, they'll finally have a timeline of recovery. From the time people came in, there's about four waves – Senku's in wave 3, and Gen had started itching around the same time Senku had, so they'll probably recover around the same time – although given that Gen was blatantly ignoring his symptoms, the mentalist might need a few more days.

That evening, Senku's about ready to drop to his knees and weep, because not only does Higuro's fever break, he asks for soup, and keeps it down. The red pockmarks are still vicious, but the man looks ten billion percent better than what he did three days ago.

Yo and Kaido's fever's break a few hours later, and Chrome definitely looks relieved when he checks up on them.

"That's actually quicker than frostgrip normally takes," he admits to Senku two days later. They're both in the exam room, with Senku finally feeling good enough to get out of bed. "It'll probably still be a few days before they're back to normal, but the fever doesn't normally break for five days with the kids anyway. I bet it's all the awesome medicine we had to offer."

Senku smiles, though he's holding a cold rag on his head. "Yeah, having a quarantine ward probably helped out a lot. If the recovery period stays on schedule, everyone will be up and running by the end of the week."

"I can't believe it," Chrome laughs. "Normally, when half the village falls sick, they're out for weeks, if not months. And there's at least one fatality. We got through this in less than a fortnight."

His face darkens. "A long, exhausting fortnight."

Senku winces. He can't argue the fact. Even if he was on the victim side, the fact that **Gen** was running most of the infirmary for the first few days is proof how how short handed they'd been.

"I need to know all the diseases the village knows about," Senku explains. "This is going to happen again, and we need to be prepared next time."

"Wait, are you sure?" Chrome asks. "I mean, you can't get frostgrip twice-"

"-And a lot of revived weren't in the village when it hit" Senku cuts in. "Which means they'll probably catch it next time."

"Not to mention all the future depetrified once we get more miracle fluid," Chrome says, eyes widening as he puts two and two together.

"It's not just frostgrip," Senku continues. "I got arrogant. I forgot that while human civilisation might have regressed, nothing else did. Disease and illness still had humans to infect, and they've always been quick to evolve. We were just lucky this one was recoverable."

Chrome looks a little horrified, but he's got that glint in his eye that comes with any challenge Senku offers.

"But we can beat them. With science, right?"

Senku grins. "Yeah. Eventually. It'll take time though. Some might not ever have a cure in our lifetime, but science will get there eventually. For now, we learn and prepare, to fight the ones we can, and prevent the ones we know."

There's a soft chuckle from outside.

"You're never satisfied unless you're fighting multiple wars, are you Senku-chan?'

"If you're out of bed Gen, I swear, I will have Koha-no, you'd enjoy that. I'll have _Magma_ tie you down!"

Chrome leans over, looking out the corner.

"He's down."

Senku scoffs. "Yeah, like that'll last. Anyway, diseases in Ishigami. Go."

Chrome grins.

"Well, I guess the next one we'd need to look out for is nightfever. It's always super bad in the winter-"

Senku leans back, allowing himself to be the student for once. Hopefully, most of the villages illnesses will be things he can counter, or he can prevent. At least until they've got the manpower and technology to have vaccines up and running again. Future chicken pox he can handle – he doesn't want to have to face stone age Spanish flu until they're several years further down the line.

For now, all he can do is prepare. One agonising illness per year is enough for him.

"The first symptoms are usually a headache that doesn't go away, and gets worse at night. What we do to stop it is-"


End file.
